Gas leak caused North Carolina plant explosion

An explosion that killed three workers at a North Carolina Slim Jim plant is said to have been caused by a natural gas leak that ignited in a room housing vacuum pumps used for sealing the snacks. It will now be up to state and federal workplace investigators to determine how the leak happened and what caused it to ignite in the blast last month at the ConAgra Foods Inc. plant in Garner.

Earl Woodham, an agent with the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives, is involved in the investigation. ATF agents believe the gas was sparked by a piece of equipment such as a fan motor or thermostat, but they said another cause, like static electricity, couldn’t be ruled out. Agent Woodham observed:

Such electrical equipment would be capable of catching natural gas on fire even if it were operating normally. It could have been anything that could have created a spark. By the very nature of the fact that whatever caused it is no longer there due the destructive explosion, we’re never going to be able to say, ‘yes this motor’ or ‘yes this thermostat’ did that.

The ATF concluded the explosion was an accident and closed its criminal investigation. The explosion ripped through the 500,000-square-foot plant in Garner while 300 people were at work. Officials said 38 employees were injured, four of them suffering critical burns. Three firefighters were treated after inhaling fumes from ammonia, which is used in the plant as a refrigerant. Some workers in and near the pump room reported smelling gas in the hours before the blast, Woodham said.

On the day of the explosion, workers were installing a new piece of equipment in the room, but it’s not clear if that played a role, according to Agent Woodham. Omaha-based ConAgra says it will assist the state Department of Labor, OSHA, and the U.S. Chemical Safety Board as they take over the investigation. The company also says it has no timetable on when the plant could be reopened. The plant has 900 employees in the town of 25,000, just south of Raleigh.